The current application of nanotechnology in food and agriculture.

Silver nanoparticles (AgNPs) have been one of the most attractive nanomaterials in biomedicine due to their unique physicochemical properties. In this paper, we review the state-of-the-art advances of AgNPs in the synthesis methods, medical applications and biosafety of AgNPs. The synthesis methods of AgNPs include physical, chemical and biological routes. AgNPs are mainly used for antimicrobial and anticancer therapy, and also applied in the promotion of wound repair and bone healing, or as the vaccine adjuvant, anti-diabetic agent and biosensors. This review also summarizes the biological action mechanisms of AgNPs, which mainly involve the release of silver ions (Ag+), generation of reactive oxygen species (ROS), destruction of membrane structure. Despite these therapeutic benefits, their biological safety problems such as potential toxicity on cells, tissue, and organs should be paid enough attention. Besides, we briefly introduce a new type of Ag particles smaller than AgNPs, silver Angstrom (A, 1 A = 0.1 nm) particles (AgAPs), which exhibit better biological activity and lower toxicity compared with AgNPs. Finally, we conclude the current challenges and point out the future development direction of AgNPs.

Silver nanoparticles: Synthesis, medical applications and biosafety

Nanotechnology has revolutionized almost all the fields of science and technology, particularly the food packaging industry Accordingly, some nanoparticles can be used in food contact materials to preserve food products for longer periods To date, many inorganic and metal nanoparticles have been implemented to synthesize active food packaging materials and to extend the shelf-life of foods Packaging with nanocomposites containing these nanoparticles offers advantages, such as reduction in the usage of preservatives and higher rate of reactions to inhibit the microbial growth Nevertheless, the safety issues of employing the metal and inorganic nanoparticles in food packaging are still a major concern and more studies along with clinical trials need to be carried out prior to the mass production of these promising food containers In this review, we have evaluated recent studies plus the applications of inorganic and metal nanoparticles mostly in food packaging applications along with their antimicrobial properties and reaction mechanisms Many examples have been provided with the aim of opening new horizons for researchers to implement inorganic and metal nanoparticles in active food packaging field

Inorganic and metal nanoparticles and their antimicrobial activity in food packaging applications

Capping agents are of utmost importance as stabilizers that inhibit the over-growth of nanoparticles and prevent their aggregation/coagulation in colloidal synthesis. The capping ligands stabilize the interface where nanoparticles interact with their medium of preparation. Specific structural features of nanoparticles are attributed to capping on their surface. These stabilizing agents play a key role in altering the biological activities and environmental perspective. Stearic effects of capping agents adsorbed on the surface of nanoparticles are responsible for such changing physico-chemical and biological characteristics. Firstly, this novel review article introduces few frequently used capping agents in the fabrication of nanoparticles. Next, recent advancements in biomedicine and environmental remediation approaches of capped nanoparticles have been elaborated. Lastly, future directions of the huge impact of capping agents on the biological environment have been summarized.

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Role of capping agents in the application of nanoparticles in biomedicine and environmental remediation: recent trends and future prospects

Green biosynthesis of silver nanoparticles using leaves extract of Artemisia vulgaris and their potential biomedical applications

Green synthesis of silver nanoparticles using Atrocarpus altilis leaf extract and the study of their antimicrobial and antioxidant activity

Green synthesis of silver nanoparticles (PAgNPs) was achieved by bio-reduction of silver nitrate using Parkia speciosa leaf aqueous extract. The PAgNPs formation was confirmed by UV–Vis spectroscopy. The synthesized silver nanoparticles in solution have shown maximum absorption at 410.5 nm, spectrophotometrically. The different parameters like temperature, pH, time, silver nitrate concentration and volume of leaf extract were optimized spectrophotometrically. The SEM, TEM and DLS analysis were used to confirm the average particle size of PAgNPs which were found to be 31 nm, 35 nm, and 155.3 d.nm, respectively. XRD and EDX analysis confirmed the nature and presence of silver. Synthesized PAgNPs showed significant photocatalytic (methylene blue under solar irradiation), antimicrobial (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus subtilis) and antioxidant (DPPH radical scavenging method) activities. The developed method for the silver nanoparticles synthesis using Parkia speciosa leaf extract is an eco-friendly and convenient method. In near future, the synthesized PAgNPs could be used in the fields of water treatment, biomedicine, biosensor and nanotechnology.

Green synthesis, characterization, antibacterial, antioxidant and photocatalytic activity of Parkia speciosa leaves extract mediated silver nanoparticles

In the present study, we have developed a green approach for the synthesis of silver nanoparticles (DSAgNPs) using aqueous extract of Durio zibethinus seed and determined its antibacterial, photocatalytic and cytotoxic effects. Surface plasmon resonance confirmed the formation of DSAgNPs with a maximum absorbance (λmax) of 420 nm. SEM and TEM images revealed DSAgNPs were spherical and rod shaped, with a size range of 20 nm and 75 nm. The zeta potential was found to be −15.41 mV. XRD and EDX analyses confirmed the nature and presence of Ag and AgCl. DSAgNPs showed considerable antibacterial activity, exhibited better cytotoxicity against brine shrimp, and shown better photocatalytic activity against methylene blue. Based on the present research work, it can be concluded that DSAgNPs could be used in the field of water treatment, pharmaceuticals, biomedicine, biosensor and nanotechnology in near future.

https://www.mdpi.com/1420-3049/23/12/3311/pdf

Phyto-Mediated Photo Catalysed Green Synthesis of Silver Nanoparticles Using Durio Zibethinus Seed Extract: Antimicrobial and Cytotoxic Activity and Photocatalytic Applications.

Background: Silver nanoparticles play a profound role in the field of biology and medicine due to its attractive physiochemical properties. Objective: The present work was aimed to develop green approach for the synthesis of silver nanoparticles (DRAgNPs) using D. zibethinus rind aqueous extract and determination of its antimicrobial and cytotoxic effect against brine shrimp. Materials and Methods: Aqueous extract of D. zibethinus rind was used to reduce silver nitrate to silver nanoparticles. The various reaction parameters were optimized, and DRAgNPs were characterized for size, shape, and nature. Results: Surface plasmon resonance confirmed the formation of DRAgNP's with maximum absorbance at λmaxof 418 nm. Scanning transmission electron microscopy and transmission electron microscope images revealed the morphology of the DRAgNPs were spherical with size range of 20 and 60 nm. Atomic force microscopy images confirmed the average particles size of DRAgNPs was to be 55 nm. The stability of the nanoparticles was also confirmed by the zeta potential which was found to be −15.82 mV. X-ray powder diffraction and energy-dispersive X-ray spectroscopy analysis confirmed the nature and the presence of Ag. DRAgNPs showed considerable antimicrobial activity against Salmonella typhimurium, Escherichia coli, Salmonella typhi, Staphylococcus aureus, Staphylococcus haemolyticus, and Bacillus subtilis, and exhibited better cytotoxicity against brine shrimp (LC50 =2.55 mg/mL). Conclusion: Based on the present study, it can be concluded that the green synthesis of silver nanoparticles using D. zibethinus rind is an eco-friendly and inexpensive method, and DRAgNPs could be used in the field of water treatment, pharmaceuticals, biomedicine, biosensor, and nanotechnology in the near future. Abbreviation used: SEM: Scanning transmission electron microscopy; TEM: Transmission electron microscope; AFM: Atomic force microscopy; XRD: X-ray powder diffraction; EDX: Energy-dispersive X-ray spectroscopy.

Sethu Vasanthi

Papers

Green synthesis of silver nanoparticles using Atrocarpus altilis leaf extract and the study of their antimicrobial and antioxidant activity

Green synthesis, characterization, antibacterial, antioxidant and photocatalytic activity of Parkia speciosa leaves extract mediated silver nanoparticles

Phyto-Mediated Photo Catalysed Green Synthesis of Silver Nanoparticles Using Durio Zibethinus Seed Extract: Antimicrobial and Cytotoxic Activity and Photocatalytic Applications.

Durio zibethinus rind extract mediated green synthesis of silver nanoparticles: Characterization and biomedical applications